Beta Lyrae (β Lyr / β Lyrae) is a binary star system approximately 882 light-years away in the constellation Lyra. Beta Lyrae is traditionally named الشلياق Sheliak which is Arabic for "tortoise" or "harp." In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. ... It has been suggested that this article or section be merged into Julian epoch. ... This article is about the star grouping. ... From the dawn of time, poop observed the sky and grouped stars into patterns or constellations. ... For other uses, see Lyra (disambiguation). ... Equatorial Coordinates Right ascension (abbrev. ... In astronomy, declination (abbrev. ... The apparent magnitude (m) of a star, planet or other celestial body is a measure of its apparent brightness as seen by an observer on Earth. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequently refined in terms of other characteristics. ... In astronomy, the color index is a simple numerical expression that determines the color of an object, which in the case of a star gives its temperature. ... In astronomy, the color index is a simple numerical expression that determines the color of an object, which in the case of a star gives its temperature. ... This article or section contains a plot summary that is overly long or excessively detailed. ... Beta Lyrae variables are a class of close binary stars. ... Illustration of the use of optical wavelength interferometry to determine precise positions of stars. ... Radial velocity is the velocity of an object in the direction of the line of sight. ... kilometre per second is an SI derived unit of both speed (scalar) and velocity (vector), signified by the symbol km/s or km s-1. ... The proper motion of a star is the motion of the position of the star in the sky (the change in direction in which we see it, as opposed to the radial velocity) after eliminating the improper motions of the stars, which affect their measured coordinates but are not real... A milliarcsecond (m, mas) , or a thoundsanth of an arcsecond. ... A year (from Old English gÄ“r) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... A milliarcsecond (m, mas) , or a thoundsanth of an arcsecond. ... A year (from Old English gÄ“r) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... For other uses, see Parallax (disambiguation). ... A milliarcsecond (m, mas) , or a thoundsanth of an arcsecond. ... Distance is a numerical description of how far apart objects are at any given moment in time. ... A light-year or lightyear (symbol: ly) is a unit of measurement of length, specifically the distance light travels in vacuum in one year. ... A parsec is the distance from the Earth to an astronomical object which has a parallax angle of one arcsecond. ... In astronomy, absolute magnitude is the apparent magnitude, m, an object would have if it were at a standard luminosity distance away from us, in the absence of interstellar extinction. ... For other uses, see Mass (disambiguation). ... In astronomy, the solar mass is a unit of mass used to express the mass of stars and larger objects such as galaxies. ... This article is about an authentication, authorization, and accounting protocol. ... In astronomy, the solar radius is a unit of length used to express the size of stars and larger objects such as galaxies. ... This article does not cite any references or sources. ... The solar luminosity, , is a unit of luminosity (power emitted in the form of photons) conventionally used by astronomers to give the luminosities of stars. ... For other uses, see Temperature (disambiguation). ... For other uses, see Kelvin (disambiguation). ... The globular cluster M80. ... This illustration shows the oblate appearance of the star Achernar caused by rapid rotation. ... This article is about the astronomical object. ... A year (from Old English gÄ“r) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... For the band of the same name, see: Binary Star (band) Hubble image of the Sirius binary system, in which Sirius B can be clearly distinguished (lower left). ... In geometry, the semi-major axis (also semimajor axis) a applies to ellipses and hyperbolas. ... For the science fiction novella by William Shunn, see Inclination (novella). ... For the band of the same name, see: Binary Star (band) Hubble image of the Sirius binary system, in which Sirius B can be clearly distinguished (lower left). ... In geometry, the semi-major axis (also semimajor axis) a applies to ellipses and hyperbolas. ... For the science fiction novella by William Shunn, see Inclination (novella). ... For the band of the same name, see: Binary Star (band) Hubble image of the Sirius binary system, in which Sirius B can be clearly distinguished (lower left). ... In geometry, the semi-major axis (also semimajor axis) a applies to ellipses and hyperbolas. ... For the science fiction novella by William Shunn, see Inclination (novella). ... For the band of the same name, see: Binary Star (band) Hubble image of the Sirius binary system, in which Sirius B can be clearly distinguished (lower left). ... In geometry, the semi-major axis (also semimajor axis) a applies to ellipses and hyperbolas. ... For the science fiction novella by William Shunn, see Inclination (novella). ... For the band of the same name, see: Binary Star (band) Hubble image of the Sirius binary system, in which Sirius B can be clearly distinguished (lower left). ... In geometry, the semi-major axis (also semimajor axis) a applies to ellipses and hyperbolas. ... For the science fiction novella by William Shunn, see Inclination (novella). ... A star catalogue, or star catalog, is an astronomical catalog that lists stars. ... In astronomy, many stars are referred to simply by catalogue numbers. ... In astronomy, many stars are referred to simply by catalogue numbers. ... The Henry Draper Catalogue is an astronomy catalogue with astrometric and spectroscopic data about more than 225,000 stars. ... Smithsonian Astrophysical Observatory Star Catalog contain the 258,996 stars. ... Fifth Fundamental Catalogue is a glossary of positions of stars. ... The Hipparcos and Tycho Catalogues (Tycho-1) are the primary products of the European Space Agencys astrometric mission, Hipparcos. ... A binary star system consists of two stars both orbiting around their barycenter. ... A light-year, symbol ly, is the distance light travels in one year: exactly 9. ... This article is about the star grouping. ... For other uses, see Lyra (disambiguation). ... Arabic can mean: From or related to Arabia From or related to the Arabs The Arabic language; see also Arabic grammar The Arabic alphabet, used for expressing the languages of Arabic, Persian, Malay ( Jawi), Kurdish, Panjabi, Pashto, Sindhi and Urdu, among others. ...

Animation showing how the light curve of a contact binary star changes as they orbit.

Beta Lyrae is an eclipsing contact binary star system made up of a blue-white dwarf (B7V) star and a white main sequence (A8V) star. The two stars are close enough that material from the photosphere of each is pulled towards the other, drawing the stars into an ellipsoid shape. Beta Lyrae is the prototype for this class of eclipsing binaries, whose components are so close together that they deform by their mutual gravitation. Image File history File links Eclipsing_binary_star_animation_3. ... Image File history File links Eclipsing_binary_star_animation_3. ... Contact binaries are a type of binary stars where both components of the binary fill their Roche lobes. ... Blue-white dwarfs are main sequence stars of spectral type B. they must be hot stars because they are blue. ... Blue-White Dwarf stars are main sequence (dwarf) stars of spectral type A. They are not to be confused with white dwarfs, which are remnants of low-mass stars. ... Solar disk redirects here. ... Animation showing how an eclipsing binary stars light intensity changes as they orbit An eclipsing binary star is a binary star in which the orbit plane of the two stars lies so nearly in the line of sight of the observer that the components undergo mutual eclipses. ...

Beta Lyrae changes its apparent magnitude from +3.4 to +4.6 over a period of 12.9075 days. The two components of the main star are so close together that they cannot be resolved with optical telescopes, forming a spectroscopic binary. The apparent magnitude (m) of a star, planet or other celestial body is a measure of its apparent brightness as seen by an observer on Earth. ... A spectroscopic binary star is a binary star which cannot be resolved as a visual binary, even with telescopes of the highest existing resolving power. ...

The system also has a third star, at an angular distance of 45.7", which is of spectral type B7V and has an apparent magnitude of +7.2 and can easily be seen with binoculars. It is about 80 times as luminous as the Sun and is also a spectroscopic binary with a period of 4.34 days. There is also another star that appears to be in the Beta lyrae system, F, magnitude 9.9v separation 86" and luminosity 7 times that of the Sun.

See also

• Beta Lyrae in fiction
• 29 Canis Majoris
• Pi Scorpii
• Ring Nebula
• Vega
• Zeta Andromedae

The planetary systems of stars other than the Sun and its Solar System are a staple element in much science fiction. ... 29 Canis Majoris (29/UW CMa) is a star in the constellation Canis Major. ... Pi Scorpii is a triple star system in the constellation Scorpius. ... The Ring Nebula (also known as the Messier 57 or NGC 6720) is located in the constellation Lyra. ... For other uses, see Vega (disambiguation). ... Zeta Andromedae (ζ And / ζ Andromedae) is a star system in the constellation Andromeda. ...

Components

Equatorial Coordinates Right ascension (abbrev. ... In astronomy, declination (abbrev. ... The apparent magnitude (m) of a star, planet or other celestial body is a measure of its apparent brightness as seen by an observer on Earth. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequenly refined in terms of other characteristics. ...

External links

• Prof. Kaler, Jim. Sheliak.
• Watching Beta Lyrae Evolve.
• Sheliak. Alcyone ephemeris.
• http://www.alcyone.de/cgi-bin/search.pl?object=HR7106